Field solution of nonlinear magnetic surface wave for a planar superconductor-antiferromagnet transmission line

A sinusoidal field solution for a nonlinear transverse magnetic surface wave in a symmetric planar transmission line made of a superconducting film and two antiferromagnets is derived. This solution enables us to investigate the propagation characteristics in the infrared frequency region. Propagation characteristics such as the attenuation constant and the phase constant are numerically analyzed as a function of the frequency, the temperature, and the thickness of a superconductor as well. In the temperature-dependent attenuation constant, it is found that there exists a characteristic temperature at which the attenuation constant attains a maximum. This characteristic temperature decreases with increasing frequency. In addition, it is seen that both the attenuation constant and the phase constant decrease with increasing thickness of a superconducting film. Finally, numerical result in the total power flow reveals that there exists a cutoff propagation constant. Electromagnetic wave can propagate through the line when the propagation constant is greater than this cutoff value.